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XvcServer

xvc_server

Trait XvcServer 

Source 
pub trait XvcServer {
    type Err: Error;

    // Required methods
    fn set_tck(&self, period_ns: u32) -> Result<u32, Self::Err>;
    fn shift(
        &self,
        num_bits: u32,
        tms: &[u8],
        tdi: &[u8],
        tdo: &mut [u8],
    ) -> Result<(), Self::Err>;
}
Expand description

Trait that backend drivers must implement to provide JTAG functionality.

This trait defines the interface between the XVC protocol server and the actual hardware debug bridge driver. Implementors are responsible for translating high-level JTAG operations into hardware-specific commands.

See the xvc-server-debugbridge crate for examples.

Required Associated Types§

Source

type Err: Error

Required Methods§

Source

fn set_tck(&self, period_ns: u32) -> Result<u32, Self::Err>

Set the TCK (Test Clock) period.

Configures the frequency of the JTAG Test Clock (TCK). The server attempts to set the requested period. If the hardware cannot achieve the exact period, it returns the closest achievable period.

§Arguments
  • period_ns - The desired TCK period in nanoseconds
§Returns

The actual TCK period set by the hardware (in nanoseconds). This may differ from the requested value if the hardware has limited frequency resolution.

§Errors

Returns Self::Err if the period cannot be configured. The XVC 1.0 protocol has no error channel, so the server logs the error and echoes the requested period back to the client to keep the reply framing intact.

Source

fn shift( &self, num_bits: u32, tms: &[u8], tdi: &[u8], tdo: &mut [u8], ) -> Result<(), Self::Err>

Shift JTAG TMS and TDI vectors into the device and capture TDO data.

Performs a JTAG shift operation by:

  1. Shifting tms and tdi data into the JTAG chain
  2. Capturing and the corresponding TDO data to tdo

The operation is atomic with respect to the JTAG state machine.

§Arguments
  • num_bits - Number of TCK cycles to perform
  • tms - Test Mode Select vector (⌈num_bits / 8⌉ bytes)
  • tdi - Test Data In vector (⌈num_bits / 8⌉ bytes)
  • tdo - Output buffer for the Test Data Out vector. The caller passes a buffer of ⌈num_bits / 8⌉ bytes; implementations must fill it completely with the captured TDO data.
§Errors

Returns Self::Err if the hardware shift fails. The XVC 1.0 protocol has no error channel, so the server cannot report the failure to the client: it logs the error and sends the current contents of tdo (zeroed by the caller) as the TDO response. Implementations should leave tdo as-is on error.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§